
CALIFORNIA MICRO DEVICES         
Micropower, 500mA Low Noise CMOS LDO Regulator 
Preliminary 
CM3019
 2004 California Micro Devices Corp.  All rights reserved
02/20/04 
430 N. McCarthy Blvd, Milpitas, California 95035        Tel: (408) 263-3214        Fax: (408) 263-7846         www.calmicro.com 
1 
Features 
 500mA output  current capability 
500mA peak in SOT-23 package 
500mA continuous in MSOP package
 500mV maximum dropout voltage at full load 
 Excellent line and load regulation 
 Stable with any output capacitor 
 Ultra low noise with optional bypass capacitor 
 Fast power-up with bypass capacitor 
 “Zero” current in Shutdown mode 
 Thermal Overload Protection  
 Foldback Current Limiting Protection 
 Reverse current protection 
Applications 
Notebook, and palmtop computers 
Cell phones and battery powered devices 
Consumer and personal electronics  
PC Card Vcc and Vpp regulation and switching 
Table 1: CM3019 Regulator Family 
Product 
CM3019-00 
CM3019-12 
CM3019-15 
CM3019-18 
CM3019-25 
CM3019-28 
CM3019-30 
CM3019-33 
For other output voltages, please contact the factory  
Output  Voltage 
Adjustable 
1.2V 
1.5V 
1.8V 
2.5V 
2.8V 
3.0V 
3.3V 
Product Description
The CM3019 is a CMOS linear voltage regulator with low 
quiescent current, very low drop out voltage and better 
than 1% initial output voltage accuracy.   
The quiescent current is typically 150μA at light loads and 
only 165μA at 500mA. This is 5% more efficient than 
equivalent Bi-CMOS devices that can waste up to 25mA at 
500mA.     
Load regulation is maintained for peak currents up to 
500mA. This is useful for supplying inrush currents during 
power-up and transient conditions. Continuous output 
current is limited by package type and board layout.  
A dedicated control input (EN, Active High) has been 
included for power-up sequencing flexibility. When this 
input is taken low, the regulator is disabled. In this state, 
the supply current will drop to near zero. 
The device also features reverse current protection. This 
protects the device by blocking the pass transistors 
parasitic diode when the output voltage is forced higher 
than the input. 
For low noise performance and increased power supply 
ripple rejection a noise bypass capacitor can be connected 
to the BYP pin. Connecting this capacitor will not 
significantly delay the speed of power-up. 
The CM3019 is fully protected, offering both overload 
current limiting and high temperature thermal shutdown.  
To reduce board cost and layout size the CM3019 was 
designed to be stable with or without any output capacitor. 
This includes tiny, low ESR ceramic capacitors.   
Housed in a low profile MSOP8 package, or a SOT23-
5/SOT23-6, the device is ideal for space critical 
applications.  
Typical Application Circuit 
Block Diagram